CN218343597U - Hydraulic steering and lifting system and dump truck - Google Patents

Abstract

The application provides a hydraulic pressure turns to and lifts system and tipper belongs to tipper technical field, and hydraulic pressure turns to and lifts the system and includes: a hydraulic oil tank; a plunger pump; an oil inlet of the switching valve bank is connected with an oil outlet of the plunger pump, and a first load sensitive port of the switching valve bank is connected with a load sensitive control oil port of the plunger pump; an oil inlet of the lifting valve bank is connected with a first oil outlet of the switching valve bank; an oil inlet of the steering valve bank is connected with a second oil outlet of the switching valve bank, and a load sensitive feedback port of the steering valve bank is connected with a second load sensitive port of the switching valve bank; and the load sensitive overflow valve bank is arranged between the load sensitive feedback port of the steering valve bank and the second load sensitive port of the switching valve bank. Through the technical scheme of this application, can realize the sensitive control of the load of turning to the system and cut off the control to the pressure of lifting the system, can guarantee the travelling comfort and the efficiency of lifting that turn to.

Description

Hydraulic steering and lifting system and dump truck

Technical Field

The application belongs to the technical field of dumper, and particularly relates to a hydraulic steering and lifting system and a dumper.

Background

The hinged mining dump truck is one kind of mining dump truck and is used widely in transporting rough and muddy open mine ore and bulk cargo. The main actions of the articulated mining dump truck are all completed through a hydraulic system, wherein the most important actions are a hydraulic steering system and a lifting system. In order to meet the requirements of good steering hand feeling and high lifting speed when the articulated mining dump truck is required to steer, a steering system generally adopts a load sensitive control mode, a lifting system generally adopts a constant pressure control mode, and in addition, the lifting system has large demand flow and the steering system has small demand flow. The prior art has at least the following problems: the steering and lifting systems of the articulated mining dump truck are mostly two completely independent systems, and each system is respectively provided with a hydraulic pump, so that the number of elements is increased, the number of pipelines is increased, and the arrangement is not facilitated.

In addition, the articulated mining dump truck has emergency steering requirements, when an engine of the vehicle breaks down, a hydraulic steering system is required to work when the trailer is required, at present, the mode of an energy accumulator and an electric pump is commonly used, but the energy accumulator occupies a large space and has limited capacity, and the electric pump needs a vehicle storage battery for power supply and cannot work for a long time. Furthermore, the road condition of the articulated mining dump truck is checked, in order to reduce the impact of fluctuation of a container caused by bumping on a lifting system, the lifting system is required to have a floating function, and the floating function is integrated on a main valve core of a lifting valve at present, so that the defects of high processing cost, large volume, high maintenance cost after damage and the like of the main valve exist.

SUMMERY OF THE UTILITY MODEL

Embodiments according to the present application aim to ameliorate at least one of the technical problems of the prior art or the related art.

In view of this, it is an object of embodiments according to the present application to provide a hydraulic steering and lifting system.

Another object according to an embodiment of the present application is to provide a dump truck.

In order to achieve the above object, according to a first aspect of the present application, there is provided a hydraulic steering and lifting system, comprising: a hydraulic oil tank; an oil inlet of the plunger pump and a leakage oil port of the plunger pump are respectively connected with the hydraulic oil tank; an oil inlet of the switching valve bank is connected with an oil outlet of the plunger pump, a first load sensitive port of the switching valve bank is connected with a load sensitive control oil port of the plunger pump, and an oil return port of the switching valve bank is connected with a hydraulic oil tank; an oil inlet of the lifting valve bank is connected with a first oil outlet of the switching valve bank, and an oil return port of the lifting valve bank is connected with a hydraulic oil tank; an oil inlet of the steering valve bank is connected with a second oil outlet of the switching valve bank, a load sensitive feedback port of the steering valve bank is connected with a second load sensitive port of the switching valve bank, and an oil return port of the steering valve bank is connected with a hydraulic oil tank; the load sensitive overflow valve bank is arranged between a load sensitive feedback port of the steering valve bank and a second load sensitive port of the switching valve bank; the oil inlet of the switching valve group is selectively communicated or disconnected with the first oil outlet of the switching valve group, and the first load sensitive port of the switching valve group is selectively communicated or disconnected with the second load sensitive port of the switching valve group.

The hydraulic steering and lifting system comprises a hydraulic oil tank, a plunger pump, a switching valve bank, a lifting valve bank, a steering valve bank and a load sensitive overflow valve bank. The plunger pump is driven by the PTO of the engine to work, an oil inlet of the plunger pump absorbs oil from a hydraulic oil tank, a leakage oil port of the plunger pump is connected with the hydraulic oil tank, an oil outlet of the plunger pump is connected with an oil inlet of the switching valve bank, and a load sensitive control oil port of the plunger pump is connected with a first load sensitive port of the switching valve bank. A first oil outlet of the switching valve group is connected with an oil inlet of the lifting valve group, a second load sensitive port of the switching valve group is connected with a load sensitive feedback port of the steering valve group, and a second oil outlet of the switching valve group is connected with an oil inlet of the steering valve group. The oil inlet of the switching valve group is selectively communicated or disconnected with the first oil outlet of the switching valve group, the first load sensitive port of the switching valve group is selectively communicated or disconnected with the second load sensitive port of the switching valve group, and the oil inlet of the switching valve group is communicated with the second oil outlet of the switching valve group, so that the load sensitive control of a steering system and the pressure cut-off control of a lifting system can be realized, and the steering comfort and the lifting efficiency can be ensured. The single plunger pump is for turning to and lifting the system fuel feeding, reduces the pipeline, and reduce cost conveniently arranges, compromises to turn to energy-conservingly, lifts the efficient requirement, and the system is the sensitive control of load during turning to, and system pressure, flow match according to the load demand, and the energy saving, the system is constant voltage control during lifting, and the plunger pump is in full discharge capacity work, and response speed is fast, lifts fastly, and efficiency is higher. The pressure requirements of a steering system and a lifting system can be met through the load sensitive overflow valve group.

In addition, the technical scheme provided by the application can also have the following additional technical characteristics:

preferably, the hydraulic steering and lifting system further comprises: the first lifting oil cylinder and the second lifting oil cylinder; an oil inlet of the first floating valve group is connected with a first working oil port of the lifting valve group, and an oil outlet of the first floating valve group is respectively connected with rod cavities of the first lifting oil cylinder and the second lifting oil cylinder; and an oil inlet of the second floating valve group is connected with a second working oil port of the lifting valve group, and an oil outlet of the second floating valve group is respectively connected with rodless cavities of the first lifting oil cylinder and the second lifting oil cylinder.

In the technical scheme, the hydraulic steering and lifting system further comprises a first lifting oil cylinder, a second lifting oil cylinder, a first floating valve group and a second floating valve group. An oil inlet of the first floating valve group is connected with a first working oil port of the lifting valve group, and an oil outlet of the first floating valve group is respectively connected with rod cavities of the first lifting oil cylinder and the second lifting oil cylinder. An oil inlet of the second floating valve group is connected with a second working oil port of the lifting valve group, and an oil outlet of the second floating valve group is respectively connected with rodless cavities of the first lifting oil cylinder and the second lifting oil cylinder. First unsteady valves and the unsteady valves of second are independent of the valves that lift, make the valves structure that lifts and control mode more simple reliable, and the maintenance of the valves that also is convenient for float and the valves that lifts is more economical and practical.

Preferably, the hydraulic steering and lifting system further comprises: a first working oil port of the steering valve group is respectively connected with a rod cavity of the first steering oil cylinder and a rodless cavity of the second steering oil cylinder, and a second working oil port of the steering valve group is respectively connected with the rodless cavity of the first steering oil cylinder and the rod cavity of the second steering oil cylinder; an oil inlet of the steering valve group is selectively communicated or disconnected with a first working oil port of the steering valve group and a second working oil port of the steering valve group.

In the technical scheme, the hydraulic steering and lifting system further comprises a first steering oil cylinder and a second steering oil cylinder. A first working oil port of the steering valve group is respectively connected with a rod cavity of the first steering oil cylinder and a rodless cavity of the second steering oil cylinder, and a second working oil port of the steering valve group is respectively connected with the rodless cavity of the first steering oil cylinder and the rod cavity of the second steering oil cylinder. When the steering wheel is rotated, pressure oil output by the plunger pump enters through an oil inlet of the switching valve group and enters an oil inlet of the steering valve group through a second oil outlet of the switching valve group, and the oil inlet of the steering valve group is communicated with the second working oil port or the first working oil port to push the first steering oil cylinder and the second steering oil cylinder to stretch and retract so as to drive the vehicle to steer.

Preferably, the switching valve group comprises a first check valve, a second check valve, a third check valve, a constant flow valve, a first throttling plug, a second throttling plug, a first electromagnetic directional valve, a logic valve and a first overflow valve; the first check valve is positioned between an oil inlet of the switching valve group and a second oil outlet of the switching valve group, and the second check valve is positioned between a second oil outlet of the switching valve group and an emergency steering oil inlet of the switching valve group; the oil inlet of the first electromagnetic directional valve is connected with the oil inlet of the switching valve group, the constant flow valve is arranged between the oil inlet of the switching valve group and the oil inlet of the first electromagnetic directional valve, the oil outlet of the first electromagnetic directional valve is connected with the second load sensitive port of the switching valve group, the second throttle plug is arranged between the oil outlet of the first electromagnetic directional valve and the second load sensitive port of the switching valve group, the third one-way valve is arranged between the first working oil port of the first electromagnetic directional valve and the second working oil port of the first electromagnetic directional valve, the first working oil port of the first electromagnetic directional valve, the oil inlet of the switching valve group and the constant flow valve are connected with the oil inlet of the logic valve, the oil outlet of the logic valve is connected with the first oil outlet of the switching valve group, and the second working oil port of the first electromagnetic directional valve is connected with the first load sensitive port of the switching valve group.

In the technical scheme, the switching valve group comprises a first check valve, a second check valve, a third check valve, a constant flow valve, a first throttle plug, a second throttle plug, a first electromagnetic directional valve, a logic valve and a first overflow valve. When the vehicle runs normally and is not lifted, the first electromagnetic reversing valve of the switching valve group is not electrified. At the moment, a load sensitive feedback port on the steering valve group is communicated with a load sensitive control port of the plunger pump through a second load sensitive port of the switching valve group, a second throttling plug and a first electromagnetic reversing valve through a first load sensitive port of the switching valve group, and the plunger pump is in a load sensitive control mode at the moment. Meanwhile, the hydraulic oil with the minimum displacement returns to the hydraulic oil tank through the first electromagnetic directional valve, the second throttling plug and the second load sensitive port of the switching valve group and the load sensitive feedback port and port of the steering valve group. The outlet pressure of the plunger pump acts on two sides of the logic valve, and because the left side of the logic valve has the spring action, the logic valve is in a left position and keeps a closed state, and pressure oil does not enter the lifting system. When the steering wheel is rotated, pressure oil output by the plunger pump enters through an oil inlet of the switching valve group, and enters an oil inlet of the steering valve group through a second oil outlet of the switching valve group via the first check valve. When lifting, the first electromagnetic reversing valve of the switching valve group is electrified, the first electromagnetic reversing valve is in the right position at the moment, pressure oil of the plunger pump passes through the oil inlet of the switching valve group, passes through the constant flow valve and the first throttling plug, acts on the load sensitive control port of the plunger pump through the first load sensitive port of the switching valve group to press the load sensitive control valve, and the plunger pump is in a pressure cut-off mode at the moment. Meanwhile, pressure oil on the left side of the logic valve flows through the first electromagnetic directional valve and the second throttling plug and is decompressed from a load sensitive feedback port of the steering valve group through a second load sensitive port of the switching valve group, the logic valve reaches a right position under the pushing of right side pressure oil, and the pressure oil output by the plunger pump enters an oil inlet of the lifting valve group through a first oil outlet.

Preferably, the hydraulic steering and lifting system further comprises: and the pilot oil source valve group is connected with a hydraulic oil tank through an oil return port.

In the technical scheme, the hydraulic steering and lifting system further comprises a pilot oil element valve bank. The pressure oil of the pilot oil source valve group comes from the control oil of other systems, the pilot oil source valve group is respectively connected with the first control port of the lifting valve group and the second control port of the lifting valve group, and the oil return port of the pilot oil source valve group is connected with the hydraulic oil tank. The lifting valve group can be controlled through the pilot oil element valve group so as to control the first lifting oil cylinder and the second lifting oil cylinder to work.

Preferably, the pilot oil element valve group comprises a pressure reducing valve, a second overflow valve, an accumulator, a third throttling plug and a second electromagnetic directional valve; an oil inlet of the pilot oil element valve group is sequentially connected with the pressure reducing valve, the third throttling plug and an oil inlet of the second electromagnetic reversing valve, a first working oil port of the second electromagnetic reversing valve is connected with a first control port of the lifting valve group, and a second working oil port of the pilot oil element valve group is connected with a second control port of the lifting valve group.

In the technical scheme, the pilot oil element valve group comprises a pressure reducing valve, a second overflow valve, an energy accumulator, a third throttling plug and a second electromagnetic reversing valve. When lifting, the second electromagnetic directional valve of the pilot oil source valve group is electrified, control oil from other systems enters from an oil inlet of the pilot oil source valve group, is decompressed through a decompression valve, enters a first control port of the lifting valve group through a first working oil port of the second electromagnetic directional valve by an upper position of a third throttling plug and the second electromagnetic directional valve, and is output to a second control port of the lifting valve group from a second working oil port of the pilot oil source valve group when descending. The accumulator is used for storing energy to enable the pilot oil source valve group to respond quickly, and the second overflow valve is used for ensuring that the pilot oil source loop is not over-pressurized.

Preferably, the hydraulic steering and lifting system further comprises: an oil inlet of the emergency pump is connected with the hydraulic oil tank; emergent steering valve group, the emergent oil inlet that turns to of switching valves links to each other with the work hydraulic fluid port of emergent steering valve group, and the work hydraulic fluid port and hydraulic tank, the emergent pump of emergent steering valve group optionally communicate.

In the technical scheme, the hydraulic steering and lifting system further comprises an emergency pump and an emergency steering valve bank. The oil inlet of emergency pump links to each other with hydraulic tank, and the emergent oil inlet that turns to of switching valves links to each other with the work hydraulic fluid port of emergent valve bank, and the work hydraulic fluid port and hydraulic tank, the optional intercommunication of emergency pump of emergent valve bank can provide power for a steering system when vehicle trouble trailer, and emergency pump and transfer case link to each other, can realize advancing, the emergent when retreating the trailer turns to.

Preferably, the emergency steering valve group comprises a first safety valve, a hydraulic control reversing valve and a fourth one-way valve; a first oil outlet of the hydraulic control reversing valve is connected with an oil outlet of the emergency steering valve group, a fourth one-way valve is arranged between the first oil outlet of the hydraulic control reversing valve and the oil outlet of the emergency steering valve group, a second oil outlet of the hydraulic control reversing valve is connected with a hydraulic oil tank, and an oil inlet of the hydraulic control reversing valve is connected with an oil outlet of the emergency pump; the emergency pump includes a bridge circuit.

In the technical scheme, the emergency steering valve group comprises a first safety valve, a hydraulic control reversing valve and a fourth one-way valve. Under the normal working condition of the vehicle, control oil from other systems enters from the opening of the emergency steering valve group to push the hydraulic control reversing valve to move upwards, and hydraulic oil output by the emergency pump driven by the transfer case PTO can be unloaded to the hydraulic oil tank from the opening through the lower position of the hydraulic control reversing valve of the emergency steering valve group. When the trailer is towed due to the failure of the vehicle engine, the control oil pressure of other systems is unloaded, the hydraulic control reversing valve moves downwards under the pushing of the spring, the pressure oil output by the emergency pump enters from the oil inlet of the emergency steering valve bank, passes through the upper position of the hydraulic control reversing valve, the fourth check valve enters into the emergency steering oil inlet of the switching valve bank, and enters into the steering valve bank from the second oil outlet of the switching valve bank through the second check valve to provide power for the steering system. The first safety valve in the emergency steering valve group and the first overflow valve in the switching valve group guarantee that the emergency steering system cannot be over-pressurized. In addition, the emergency pump integrates a bridge type loop consisting of 4 one-way valves, so that the emergency pump can absorb and discharge oil from the same oil port no matter the wheels rotate forwards or reversely.

Preferably, the lift valve block comprises a fifth one-way valve, a second relief valve and a main spool; an oil inlet of the main valve core is connected with an oil inlet of the lifting valve group, the fifth check valve is located between the oil inlet of the main valve core and the oil inlet of the lifting valve group, and the oil inlet of the main valve core is selectively communicated or disconnected with the oil inlet of the first floating valve group and the oil inlet of the second floating valve group.

In the technical scheme, the lifting valve group comprises a fifth one-way valve, a second safety valve and a main valve core. When the lifting valve is lifted, under the pushing of pressure oil, a main valve core of the lifting valve group moves to the right, the pressure oil from the switching valve group passes through a fifth one-way valve, the left position of the main valve core enters rodless cavities of the first lifting oil cylinder and the second lifting oil cylinder through the first floating valve group and the second floating valve group, so that the lifting oil cylinders extend out, and a container is lifted. And hydraulic oil in rod cavities of the first lifting oil cylinder and the second lifting oil cylinder returns to a hydraulic oil tank through the first floating valve group, the second floating valve group, the lifting valve group and a main valve core of the lifting valve group. When the container descends, the main valve core of the lifting valve group moves leftwards under the pushing of the control oil pressure, pressure oil input from an oil inlet of the lifting valve group enters the rod cavity of the lifting oil cylinder through the fifth one-way valve and the right position of the main valve core, the lifting valve group, the first floating valve group and the second floating valve group to push the oil cylinder to retract, and the container descends. And hydraulic oil in the rodless cavity of the lifting oil cylinder returns to the hydraulic oil tank through the first floating valve group, the second floating valve group and an oil return port of the lifting valve group.

In order to achieve the second object of the present application, a technical solution of a second aspect of the present application provides a dump truck, including: a hydraulic steering and lifting system according to any of the claims in the first aspect of the present application.

According to the technical scheme of this application, the dump truck that provides includes the hydraulic steering and lifting system as in any one of the technical schemes in this application first aspect, therefore it has the hydraulic steering and lifting system as in any one of the technical schemes in this application first aspect and all beneficial effects, and no longer repeated here. Wherein, the tipper includes articulated mining tipper.

Additional aspects and advantages of embodiments in accordance with the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments in accordance with the present application.

Drawings

FIG. 1 is a schematic illustration of the operation of a hydraulic steering and lifting system according to one embodiment provided herein;

FIG. 2 is a schematic illustration of the operation of a hydraulic steering and lifting system according to another embodiment provided herein.

Wherein, the correspondence between the reference numbers and the component names in fig. 1 and fig. 2 is:

10: a hydraulic steering and lifting system; 100: a hydraulic oil tank; 110: a plunger pump; 112: a load-sensitive control valve; 120: switching valve groups; 122: a first check valve; 124: a second one-way valve; 126: a third check valve; 128: a constant flow valve; 130: a lifting valve group; 132: a fifth check valve; 134: a second relief valve; 136: a main valve element; 140: a steering valve bank; 150: a load-sensitive overflow valve bank; 160: a first lift cylinder; 170: a second lifting cylinder; 180: a first floating valve group; 190: a second floating valve group; 200: a first steering cylinder; 210: a second steering cylinder; 220: a first choke plug; 222: a second choke plug; 224: the first electromagnetic directional valve: 226: a logic valve: 228: a first overflow valve; 230: a pilot oil valve group; 232: a pressure reducing valve; 234: a second overflow valve; 236: an accumulator; 238: a third choke plug; 240: a second electromagnetic directional valve; 250: an emergency pump; 260: an emergency steering valve group; 262: a first safety valve; 264: a hydraulic control directional control valve; 266: and a fourth check valve.

Detailed Description

In order that the above objects, features and advantages of embodiments according to the present application may be more clearly understood, embodiments according to the present application will be described in further detail below with reference to the accompanying drawings and detailed description. It should be noted that features of embodiments according to the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments according to the present application, however, embodiments according to the present application may be practiced in other ways than those described herein, and therefore, the scope of protection afforded by embodiments according to the present application is not limited by the specific embodiments disclosed below.

Some embodiments provided in accordance with the present application are described below with reference to fig. 1 and 2.

Referring to fig. 1, a hydraulic steering and lifting system 10 according to an embodiment of the present application includes a hydraulic tank 100, a plunger pump 110, a switching valve block 120, a lifting valve block 130, a steering valve block 140, and a load sensitive spill valve block 150. Specifically, an oil inlet of the plunger pump 110 and an oil leakage port of the plunger pump 110 are respectively connected to the hydraulic oil tank 100. An oil inlet of the switching valve group 120 is connected with an oil outlet of the plunger pump 110, a first load-sensitive port of the switching valve group 120 is connected with a load-sensitive control oil port of the plunger pump 110, and an oil return port of the switching valve group 120 is connected with the hydraulic oil tank 100. An oil inlet of the lifting valve set 130 is connected with a first oil outlet of the switching valve set 120, and an oil return port of the lifting valve set 130 is connected with the hydraulic oil tank 100. An oil inlet of the steering valve group 140 is connected with a second oil outlet of the switching valve group 120, a load sensitive feedback port of the steering valve group 140 is connected with a second load sensitive port of the switching valve group 120, and an oil return port of the steering valve group 140 is connected with the hydraulic oil tank 100. A load sensitive spill valve block 150 is provided between the load sensitive feedback port of the divert valve block 140 and the second load sensitive port of the switch valve block 120. Wherein, the oil inlet of the switching valve group 120 is selectively connected or disconnected with the first oil outlet of the switching valve group 120 and the second oil outlet of the switching valve group 120.

The hydraulic steering and lifting system 10 provided in accordance with the present embodiment includes a hydraulic tank 100, a plunger pump 110, a switching valve block 120, a lifting valve block 130, a steering valve block 140, and a load sensitive spill valve block 150. The plunger pump 110 is driven by the engine PTO to work, an oil inlet of the plunger pump 110 sucks oil from the hydraulic oil tank 100, a leakage oil port of the plunger pump 110 is connected with the hydraulic oil tank 100, an oil outlet of the plunger pump 110 is connected with an oil inlet of the switching valve group 120, and a load sensitive control oil port of the plunger pump 110 is connected with a first load sensitive port of the switching valve group 120. The first oil outlet of the switching valve group 120 is connected with the oil inlet of the lifting valve group 130, the second load sensitive port of the switching valve group 120 is connected with the load sensitive feedback port of the steering valve group 140, and the second oil outlet of the switching valve group 120 is connected with the oil inlet of the steering valve group 140. An oil inlet of the switching valve group 120 is selectively communicated or disconnected with a first oil outlet of the switching valve group 120, a first load sensitive port of the switching valve group 120 is selectively communicated or disconnected with a second load sensitive port of the switching valve group 120, and an oil inlet of the switching valve group 120 is communicated with a second oil outlet of the switching valve group 120, so that steering comfort and lifting efficiency can be guaranteed. The single plunger pump 110 supplies oil for a steering and lifting system, pipelines are reduced, the cost is reduced, the arrangement is convenient, the steering energy-saving and efficient lifting requirements are met, the system is in load sensitive control during steering, the pressure and the flow of the system are matched according to load requirements, the energy is saved, the system is in constant pressure control during lifting, the plunger pump 110 works at full displacement, the response speed is high, the lifting speed is high, and the efficiency is higher. The requirement of the pressure of the steering system and the pressure of the lifting system can be met through the load sensitive overflow valve group 150.

Specifically, when the vehicle is running normally and not lifted, the load-sensitive feedback port on the steering valve set 140 is communicated with the load-sensitive control port of the plunger pump 110 through the second load-sensitive port of the switching valve set 120, the second throttle plug 222, the first electromagnetic directional valve 224 and the first load-sensitive port of the switching valve set 120, and at this time, the plunger pump 110 is in the load-sensitive control mode. When the steering wheel is not moved, the steering valve group 140 is kept at the middle position, the oil inlet of the steering valve group 140 is closed, the steering oil cylinder does not work, no load feedback signal acts on the load sensitive control port of the plunger pump 110 at the moment, and the plunger pump 110 works at standby pressure and minimum displacement. When the steering wheel is turned, the pressure oil output by the plunger pump 110 enters through the oil inlet of the switching valve group 120 and enters the oil inlet of the steering valve group 140 through the second oil outlet of the switching valve group 120, the steering valve group 140 drives the vehicle to steer, and because the system is in a load-sensitive control state, the plunger pump 110 can output corresponding displacement and pressure according to the requirements of the first steering oil cylinder 200 and the second steering oil cylinder 210. The function of the load sensitive spill valve train 150 is to ensure that the steering system pressure does not exceed the system set point. When the plunger pump 110 is lifted, the pressure oil of the plunger pump 110 passes through the oil inlet of the switching valve set 120, and acts on the load-sensitive control port of the plunger pump 110 through the first load-sensitive port of the switching valve set 120 to lock the load-sensitive control valve 112, and the plunger pump 110 is in the pressure-cut-off mode. Meanwhile, the pressurized oil output from the plunger pump 110 enters the oil inlet of the lift valve set 130 through the first oil outlet, so that the cargo box is lifted and lowered.

In the above embodiment, the hydraulic steering and lifting system 10 further comprises a first lift cylinder 160, a second lift cylinder 170, a first float valve set 180, and a second float valve set 190. An oil inlet of the first floating valve group 180 is connected with a first working oil port of the lifting valve group 130, and an oil outlet of the first floating valve group 180 is connected with rod cavities of the first lifting oil cylinder 160 and the second lifting oil cylinder 170 respectively. An oil inlet of the second floating valve group 190 is connected with a second working oil port of the lifting valve group 130, and an oil outlet of the second floating valve group 190 is connected with rodless cavities of the first lifting oil cylinder 160 and the second lifting oil cylinder 170 respectively. First floating valve set 180 and second floating valve set 190 are independent of lifting valve set 130, so that the structure and control mode of lifting valve set 130 are simpler and more reliable, maintenance of floating valve set and lifting valve set 130 is facilitated, and the valve set is more economical and practical. The first floating valve set 180 includes a third electromagnetic directional valve, and the second floating valve set includes a fourth electromagnetic directional valve.

Specifically, when the floating button is pressed, the first electromagnetic directional valve 224 of the switching valve group 120 and the second electromagnetic directional valve 240 of the pilot oil source valve group are not energized, and the third electromagnetic directional valve and the fourth electromagnetic directional valve are energized simultaneously, and at this time, the rod chambers and the rodless chambers of the first lift cylinder 160 and the second lift cylinder 170 are communicated with the hydraulic oil tank 100 through the first floating valve group 180 and the second floating valve group 190. The container can descend under the action of the gravity of the container or impact on a lifting system caused by a bumpy road surface is reduced.

Further, as shown in fig. 2, the lift valve block 130 includes a fifth check valve 132, a second relief valve 134, and a main spool 136. An oil inlet of the main valve element 136 is connected to an oil inlet of the lift valve set 130, the fifth check valve 132 is located between the oil inlet of the main valve element 136 and the oil inlet of the lift valve set 130, and the oil inlet of the main valve element 136 is selectively connected or disconnected with an oil inlet of the first floating valve set 180 and an oil inlet of the second floating valve set 190. When lifting, under the push of pressure oil, the main valve spool 136 of the lifting valve set 130 moves to the right, the pressure oil from the switching valve set 120 passes through the fifth check valve 132, the left position of the main valve spool 136 enters the rodless cavities of the first lifting cylinder 160 and the second lifting cylinder 170 through the first floating valve set 180 and the second floating valve set 190 to extend the lifting cylinders, and then the container is lifted. The hydraulic fluid in the rod chambers of first lift cylinder 160 and second lift cylinder 170 passes through first and second float valve sets 180 and 190, through lift valve set 130, and back to hydraulic reservoir 100 through main spool 136 of lift valve set 130. When the cargo box descends, under the pushing action of the control oil pressure, the main valve core 136 of the lift valve group 130 moves leftwards, the pressure oil input from the oil inlet of the lift valve group 130 enters the rod cavity of the lift oil cylinder through the fifth check valve 132 and the right position of the main valve core 136, the lift valve group 130, the first floating valve group 180 and the second floating valve group 190 to push the oil cylinder to retract, and the cargo box descends. The hydraulic oil in the rodless cavity of the lifting oil cylinder returns to the hydraulic oil tank 100 through the oil return ports of the first floating valve group 180, the second floating valve group 190 and the lifting valve group 130.

In some embodiments, the hydraulic steering and lifting system 10 further includes a first steering cylinder 200 and a second steering cylinder 210. A first working oil port of the steering valve group 140 is connected to a rod chamber of the first steering cylinder 200 and a rodless chamber of the second steering cylinder 210, respectively, and a second working oil port of the steering valve group 140 is connected to a rodless chamber of the first steering cylinder 200 and a rod chamber of the second steering cylinder 210, respectively. When the steering wheel is rotated, the pressure oil output by the plunger pump 110 enters through the oil inlet of the switching valve set 120 and enters the oil inlet of the steering valve set 140 through the second oil outlet of the switching valve set 120, and the oil inlet of the steering valve set 140 is communicated with the second working oil port or the first working oil port to push the first steering oil cylinder 200 and the second steering oil cylinder 210 to stretch and retract so as to drive the vehicle to steer. Wherein the steering valve set 140 may be a hydraulic steering gear.

As shown in fig. 2, in the above embodiment, the switching valve group 120 includes the first check valve 122, the second check valve 124, the third check valve 126, the constant flow valve 128, the first choke plug 220, the second choke plug 222, the first solenoid directional valve 224, the logic valve 226, and the first overflow valve 228. The first check valve 122 is located between an oil inlet of the switching valve group 120 and a second oil outlet of the switching valve group 120, and the second check valve 124 is located between the second oil outlet of the switching valve group 120 and an emergency steering oil inlet of the switching valve group 120. An oil inlet of the first electromagnetic directional valve 224 is connected with an oil inlet of the switching valve group 120, the constant flow valve 128 and the first throttling plug 220 are arranged between the oil inlet of the switching valve group 120 and the oil inlet of the first electromagnetic directional valve 224, an oil outlet of the first electromagnetic directional valve 224 is connected with the second load sensitive port of the switching valve group 120, the second throttling plug 222 is arranged between an oil outlet of the first electromagnetic directional valve 224 and the second load sensitive port of the switching valve group 120, the third check valve 126 is arranged between a first working oil port of the first electromagnetic directional valve 224 and a second working oil port of the first electromagnetic directional valve 224, a first working oil port of the first electromagnetic directional valve 224, an oil inlet of the switching valve group 120 and the constant flow valve 128 are all connected with an oil inlet of the logic valve 226, an oil outlet of the logic valve 226 is connected with the first oil outlet of the switching valve group 120, and the second working oil port of the first electromagnetic directional valve 224 is connected with the first load sensitive port of the switching valve group 120.

When the vehicle is normally running and not lifted, the first electromagnetic directional valve 224 of the switching valve set 120 is not electrified. At this time, the load-sensitive feedback port on the steering valve block 140 is communicated with the load-sensitive control port of the plunger pump 110 through the second load-sensitive port of the switching valve block 120, the second throttle plug 222, the first electromagnetic directional valve 224, and the first load-sensitive port of the switching valve block 120, and at this time, the plunger pump 110 is in the load-sensitive control mode. Meanwhile, the minimum displacement hydraulic oil returns to the hydraulic oil tank 100 through the first electromagnetic directional valve 224, the second throttle plug 222 and the second load-sensitive port of the switching valve group 120, and the load-sensitive feedback port and the port of the steering valve group 140. The outlet pressure of the plunger pump 110 acts on both sides of the logic valve 226, and because of the spring action on the left side of the logic valve 226, the logic valve 226 remains closed in the left position and pressurized oil does not enter the lift system. When the steering wheel is turned, the pressure oil output by the plunger pump 110 enters through the oil inlet of the switching valve set 120, and passes through the first check valve 122, and the second oil outlet of the switching valve set 120 enters the oil inlet of the steering valve set 140. When lifting, the first electromagnetic directional valve 224 of the switching valve group 120 is powered, at this time, the first electromagnetic directional valve 224 is in the right position, the pressure oil of the plunger pump 110 passes through the oil inlet of the switching valve group 120, passes through the constant flow valve 128, the first throttle plug 220, acts on the load-sensitive control port of the plunger pump 110 through the first load-sensitive port of the switching valve group 120 to push the load-sensitive control valve 112, at this time, the plunger pump 110 is in the pressure cut-off mode. Meanwhile, pressure oil on the left side of the logic valve 226 passes through the first electromagnetic directional valve 224 and the second throttle plug 222, and is discharged from a load-sensitive feedback port of the steering valve bank 140 through a second load-sensitive port of the switching valve bank 120, the logic valve 226 reaches a right position under the pushing of the right pressure oil, and the pressure oil output by the plunger pump 110 enters an oil inlet of the lifting valve bank 130 through a first oil outlet.

In some embodiments, the hydraulic steering and lifting system 10 further includes a pilot oil unit valve block 230. The pressure oil of the pilot oil source valve group comes from the control oil of other systems, the pilot oil source valve group 230 is respectively connected with the first control port of the lifting valve group 130 and the second control port of the lifting valve group 130, and the oil return port of the pilot oil source valve group is connected with the hydraulic oil tank 100. The lift valve assembly 130, and thus the first lift cylinder 160 and the second lift cylinder 170, can be controlled to operate by the pilot oil unit valve assembly 230.

Further, the pilot oil unit valve group 230 includes a pressure reducing valve 232, a second relief valve 234, an accumulator 236, a third choke 238 and a second solenoid directional valve 240. An oil inlet of the pilot oil element valve group 230 is sequentially connected with a pressure reducing valve 232, a third throttling plug 238 and an oil inlet of a second electromagnetic directional valve 240, a first working oil port of the second electromagnetic directional valve 240 is connected with a first control port of the lifting valve group 130, and a second working oil port of the pilot oil element valve group 230 is connected with a second control port of the lifting valve group 130. When the valve assembly is lifted, the second electromagnetic directional valve 240 of the pilot oil source valve group is powered, control oil from other systems enters from an oil inlet of the pilot oil source valve group, is decompressed by the decompression valve 232, enters the first control port of the lifting valve group 130 through the first working oil port of the second electromagnetic directional valve 240 by the third throttling plug 238 and the upper position of the second electromagnetic directional valve 240, and is output to the second control port of the lifting valve group 130 from the second working oil port of the pilot oil source valve group when the valve assembly is lowered. Accumulator 236 functions to store energy to enable the pilot source valve set to respond quickly, and second relief valve 234 functions to ensure that the pilot source circuit is not over-pressurized.

In some embodiments, the hydraulic steering and lifting system 10 further includes an emergency pump 250 and an emergency steering valve set 260. An oil inlet of the emergency pump 250 is connected with the hydraulic oil tank 100, an emergency steering oil inlet of the switching valve group 120 is connected with a working oil port of the emergency steering valve group 260, the working oil port of the emergency steering valve group 260 is selectively communicated with the hydraulic oil tank 100 and the emergency pump 250, power can be provided for a steering system when a vehicle is in a fault trailer, and the emergency pump 250 is connected with the transfer case, so that emergency steering during forward and backward towing can be realized.

Further, the emergency divert valve set 260 includes a first relief valve 262, a pilot operated directional valve 264, and a fourth check valve 266. Under the normal working condition of the vehicle, control oil from other systems enters from the port of the emergency steering valve set 260 to push the hydraulic control reversing valve 264 to move upwards, and hydraulic oil output by the emergency pump 250 driven by the transfer case PTO can be unloaded from the port to the hydraulic oil tank 100 through the lower position of the hydraulic control reversing valve 264 of the emergency steering valve set 260. When the vehicle engine is in failure to tow a trailer, the control oil pressure of other systems is unloaded, the hydraulic control reversing valve 264 is pushed by the spring to move downwards, the pressure oil output by the emergency pump 250 enters from the oil inlet of the emergency steering valve group 260, passes through the upper position of the hydraulic control reversing valve 264, enters into the emergency steering oil inlet of the switching valve group 120 through the fourth check valve 266, and enters into the steering valve group 140 from the second oil outlet of the switching valve group 120 through the second check valve 124 to provide power for the steering system. Wherein the first relief valve 262 in the emergency steering valve set 260 and the first relief valve 228 in the switching valve set 120 are to ensure that the emergency steering system is not over pressurized. In addition, the emergency pump 250 integrates a bridge type loop consisting of 4 one-way valves, so that the emergency pump 250 can absorb and discharge oil from the same oil port no matter the wheels rotate forwards or reversely.

Embodiments of the second aspect of the present application provide a dump truck comprising a hydraulic steering and lifting system 10 as described in any of the embodiments above.

According to the dump truck provided by the embodiment of the present application, the dump truck comprises the hydraulic steering and lifting system 10 according to any one of the above embodiments, so that the dump truck has all the advantages of the hydraulic steering and lifting system 10 according to any one of the above embodiments, and the detailed description thereof is omitted. Wherein, the tipper includes articulated formula mining tipper.

As shown in fig. 1 and 2, a hydraulic steering and lifting system 10 according to an embodiment of the present disclosure includes a hydraulic oil tank 100, a plunger pump 110, a switching valve set 120, a pilot oil unit valve set 230, a lifting valve set 130, a first floating valve set 180, a second floating valve set 190, a first lifting cylinder 160 and a second lifting cylinder 170, a first steering cylinder 200 and a second steering cylinder 210, a hydraulic steering gear, a load-sensitive overflow valve set 150, an emergency steering valve set 260, and an emergency pump 250. The plunger pump 110 is driven by the engine PTO to work, an oil inlet S of the plunger pump 110 sucks oil from the hydraulic oil tank 100, a port T2 of the plunger pump is a leakage oil port and is connected with the hydraulic oil tank 100, and an oil outlet P of the plunger pump 110 is connected with an oil inlet P of the switching valve group 120; the load sensitive control port PL of the plunger pump 110 is connected to a first load sensitive port PLs of the switching valve block 120. The first oil outlet LV of the switching valve group 120 is connected with the oil inlet P of the lifting valve group 130, the oil return port T of the switching valve group 120 is connected with the hydraulic oil tank 100, the second load sensitive port SLS of the switching valve group 120 is connected with the load sensitive feedback port LS of the hydraulic steering gear, the emergency steering oil inlet E of the switching valve group 120 is connected with the oil outlet A of the emergency steering valve group 260, and the second oil outlet S of the switching valve group 120 is connected with the oil inlet P of the hydraulic steering gear. The pressure oil of the pilot oil source valve group comes from control oil of other systems and enters the pilot oil source valve group through a P port; a first working oil port a and a second working oil port B of the pilot oil source valve group are respectively connected with a first control port a and a second control port B of the lifting valve group 130, and an oil return port T of the pilot oil source valve group is connected with the hydraulic oil tank 100. A first working oil port A1 and a second working oil port B1 of the lifting valve group 130 are respectively connected to an oil inlet of the first floating valve group 180 and an oil inlet of the second floating valve group 190, and an oil return port T of the lifting valve group 130 is connected to the hydraulic oil tank 100. The oil outlets of the first floating valve group 180 are respectively connected with rod cavities of the first lifting oil cylinder 160 and the second lifting oil cylinder 170, the oil outlets of the second floating valve group 190 are respectively connected with rodless cavities of the first lifting oil cylinder 160 and the second lifting oil cylinder 170, and oil return ports T of the first floating valve group 180 and the second floating valve group 190 are connected with the hydraulic oil tank 100. A first working oil port R of the hydraulic steering gear is connected to a rod cavity of the first steering cylinder 200 and a rodless cavity of the second steering cylinder 210, a second working oil port of the steering valve group 140 is connected to the rodless cavity of the first steering cylinder 200 and the rod cavity of the second steering cylinder 210, respectively, and an oil return port T of the hydraulic steering gear is connected to the hydraulic oil tank 100. The load sensitive spill valve block 150 is connected in parallel in the line between the load sensitive feedback port LS of the hydraulic steering gear and the second load sensitive port SLS of the switch valve block 120. The emergency pump 250 is driven by the transfer case PTO, draws oil from the hydraulic oil tank 100, and delivers the hydraulic oil to the oil inlet P of the emergency steering valve group 260 through the oil outlet P. The port B of the emergency steering valve set 260 is connected with control oil from other systems, and the working oil port a of the emergency steering valve set 260 is connected with the port E of the emergency steering oil inlet of the switching valve set 120.

Wherein, a single plunger pump 110 supplies oil for the hydraulic steering and lifting system 10, which can reduce the number of pipelines, reduce the cost and facilitate the arrangement. The hydraulic steering and lifting system 10 meets the requirements of steering energy conservation and high lifting efficiency, the system is in load sensitive control during steering, the pressure and the flow of the system are matched according to the load requirement, energy is saved, the system is in constant pressure control during lifting, the plunger pump 110 works at full displacement, the response speed is high, the lifting speed is high, and the efficiency is higher.

When the vehicle is running normally and not lifting, the first electromagnetic directional valve 224 of the switching valve set 120 is not powered and is in the left position as shown in the figure. At this time, the load-sensitive feedback port LS of the hydraulic steering gear is communicated with the load-sensitive control port PL of the plunger pump 110 through the second load-sensitive port SLS of the switching valve block 120, the second choke plug 222, the first electromagnetic directional valve 224, and the first load-sensitive port PLS of the switching valve block 120, and at this time, the plunger pump 110 is in the load-sensitive control mode. When the steering wheel is not moved, the hydraulic steering gear is kept at a middle position, an oil inlet P of the hydraulic steering gear is closed, the steering oil cylinder does not work, no-load feedback signals act on a load sensitive control port PL of the plunger pump 110 at the moment, and the plunger pump 110 works at standby pressure and minimum displacement. At this time, the hydraulic oil with the minimum displacement output from the oil outlet P of the plunger pump 110 passes through the oil inlet P of the switching valve group 120, passes through the constant flow valve 128, the first throttle plug 220, the first electromagnetic directional valve 224 and the third check valve 126, and a standby pressure signal is acted on the load-sensitive control port PL of the plunger pump 110 through the first load-sensitive port PLS of the switching valve group 120, so that a pressure signal is always acted on the load-sensitive control valve 112, and thus, the swash plate response speed of the plunger pump 110 can be improved. Meanwhile, the minimum displacement hydraulic oil returns to the hydraulic oil tank 100 through the first electromagnetic directional valve 224, the second throttle plug 222, the second load sensitive port SLS of the switching valve group 120, and the load sensitive feedback ports LS and T of the hydraulic steering gear. The outlet pressure of the plunger pump 110 acts on both sides of the logic valve 226, and because of the spring action on the left side of the logic valve 226, the logic valve 226 remains closed in the left position and pressurized oil does not enter the lift system.

When the steering wheel is rotated, pressure oil output by the plunger pump 110 enters through an oil inlet P of the switching valve group 120, enters an oil inlet P of the hydraulic steering gear through the first check valve 122 and a second oil outlet S of the switching valve group 120, the oil inlet P of the hydraulic steering gear is communicated with the second working oil port L or the first working oil port R, the first steering oil cylinder 200 and the second steering oil cylinder 210 are pushed to stretch and retract, so that the vehicle is driven to steer, and the plunger pump 110 outputs corresponding displacement and pressure according to the requirements of the first steering oil cylinder 200 and the second steering oil cylinder 210 because the system is in a load sensitive control state. The function of the load sensitive spill valve train 150 is to ensure that the steering system pressure does not exceed the system set point. When the steering wheel is turned, the switching valve set 120 applies the pressure signal output by the plunger pump 110 to the load-sensitive control valve of the plunger pump 110 through the first electromagnetic directional valve 224 and the third check valve 126, so that the plunger pump 110 can respond quickly and output sufficient pressure and flow when the steering wheel is turned.

When lifting, the first electromagnetic directional valve 224 of the switching valve group 120 and the second electromagnetic directional valve 240 of the pilot oil source valve group are simultaneously powered, at this time, the first electromagnetic directional valve 224 is in the right position, the pressure oil of the plunger pump 110 passes through the oil inlet P of the switching valve group 120, passes through the constant flow valve 128, the first throttle plug 220, acts on the load sensitive control port PL of the plunger pump 110 through the first load sensitive port PLS of the switching valve group 120 to press the load sensitive control valve 112, and at this time, the plunger pump 110 is in the pressure cut-off mode. Meanwhile, pressure oil on the left side of the logic valve 226 passes through the first electromagnetic directional valve 224 and the second throttle plug 222, and is discharged from a load sensitive feedback port LS of the hydraulic steering gear through a second load sensitive port SLS of the switching valve group 120, the logic valve 226 reaches a right position under the pushing of right pressure oil, and the pressure oil output by the plunger pump 110 enters an oil inlet P of the lifting valve group 130 through a first oil outlet LV. Control oil from other systems enters from an oil inlet P of the pilot oil source valve bank, passes through the pressure reduction of the pressure reducing valve 232, enters a first control port a of the lifting valve bank 130 through a first working oil port A of the second electromagnetic reversing valve 240 by the upper positions of a third throttling plug 238 and the second electromagnetic reversing valve 240, the energy accumulator 236 is used for storing energy, the pilot oil source valve bank can respond quickly, and the second overflow valve 234 is used for ensuring that a pilot oil source loop is not overpressured. Under the push of the pressure oil, the main valve 136 of the lift valve set 130 moves to the right, the pressure oil from the switching valve set 120 passes through the fifth check valve 132, the left position of the main valve 136 enters the rodless cavities of the first lift cylinder 160 and the second lift cylinder 170 through the port A1, and the ports A2 and B2 of the first floating valve set 180 and the second floating valve set 190, so that the lift cylinders extend out, and the container is lifted. The hydraulic oil in the rod chambers of the first lift cylinder 160 and the second lift cylinder 170 flows through ports B3 and A3 of the first floating valve set 180 and the second floating valve set 190, and port B1 of the lift valve set 130, and returns to the hydraulic oil tank 100 through the main spool 136 of the lift valve set 130.

When the cargo box descends, the first electromagnetic directional valve 224 of the switching valve group 120 and the second electromagnetic directional valve 240 of the pilot oil source valve group are simultaneously powered, the control oil is output from the second working oil port B of the pilot oil source valve group to the second control port B of the lifting valve group 130, the main valve element 136 of the lifting valve group 130 moves to the left under the pushing of the pressure of the control oil, the pressure oil input from the oil inlet P of the lifting valve group 130 passes through the fifth check valve 132 and the right position of the main valve element 136, and passes through the port B1 of the lifting valve group 130, the ports A3 and B3 of the first floating valve group 180 and the second floating valve group 190 enter the lifting cylinder to push the cylinder to retract, and the cargo box descends. The hydraulic oil in the rodless cavity of the lifting oil cylinder returns to the hydraulic oil tank 100 through the ports B2 and A2 of the first floating valve group 180 and the second floating valve group 190 and the oil return port T of the lifting valve group 130.

When the floating button is pressed, the first electromagnetic directional valve 224 of the switching valve group 120 and the second electromagnetic directional valve 240 of the pilot oil source valve group are not powered, the third electromagnetic directional valve and the fourth electromagnetic directional valve of the floating valve group are powered at the same time, and at the moment, the rod cavities and the rodless cavities of the first lifting oil cylinder 160 and the second lifting oil cylinder 170 are communicated with the hydraulic oil tank 100 through the first floating valve group 180 and B2, T2, B3 and T3 of the second floating valve group 190. The container can descend under the action of the gravity of the container or impact on a lifting system caused by a bumpy road surface is reduced. It can be understood that the first floating valve set 180 and the second floating valve set 190 are independent of the lifting valve set 130, so that the structure and the control mode of the lifting valve set 130 are simpler and more reliable, the maintenance of the first floating valve set 180, the second floating valve set 190 and the lifting valve set 130 is facilitated, and the valve set is more economical and practical.

Under the normal working condition of the vehicle, control oil from other systems enters from the port B of the emergency steering valve set 260 to push the hydraulic control directional valve 264 to move upwards, and hydraulic oil output by the emergency pump 250 driven by the transfer case PTO (the rotation of which is consistent with the rotation of the wheels) is unloaded from the port T to the hydraulic oil tank 100 through the lower position of the hydraulic control directional valve 264 of the emergency steering valve set 260. When the vehicle engine is in failure to tow a trailer, the control oil pressure of other systems is unloaded, the hydraulic control reversing valve 264 is pushed by the spring to move downwards, the pressure oil output by the emergency pump 250 enters from the oil inlet P of the emergency steering valve group 260, passes through the upper position of the hydraulic control reversing valve 264, enters the emergency steering oil inlet of the switching valve group 120 through the fourth check valve 266, and enters the hydraulic steering gear from the second oil outlet S of the switching valve group 120 through the second check valve 124 to provide power for the steering system. Wherein the first relief valve 262 in the emergency steering valve set 260 and the first relief valve 228 in the switching valve set 120 are to ensure that the emergency steering system is not over pressurized. In addition, the emergency pump 250 integrates a bridge-type loop consisting of 4 one-way valves, so that the emergency pump 250 can absorb and discharge oil from the same oil port no matter the wheels rotate forwards or backwards (the vehicle moves forwards or backwards). By designing the emergency pump 250 and the emergency steering valve group 260 which can rotate in two directions, power can be provided for a steering system when the vehicle is in a fault trailer.

In embodiments according to the present application, the terms "first", "second", "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The terms "mounted," "connected," "fixed," and the like are used broadly and should be construed to include, for example, "connected" may be a fixed connection, a detachable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. Specific meanings of the above terms in the embodiments according to the present application can be understood by those of ordinary skill in the art as the case may be.

In the description of the embodiments according to the present application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, only for convenience of description and simplification of description of the embodiments according to the present application, and do not indicate or imply that the referred devices or units must have a specific direction, be configured and operated in a specific orientation, and thus, cannot be construed as limitations on the embodiments according to the present application.

In the description of the present specification, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example in accordance with the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above embodiments are merely preferred embodiments according to the present application, and are not intended to limit the embodiments according to the present application, and those skilled in the art may make various modifications and variations to the embodiments according to the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the embodiments according to the present application shall be included in the protection scope of the embodiments according to the present application.

Claims (10)

1. A hydraulic steering and lifting system, comprising:

a hydraulic oil tank (100);

an oil inlet of the plunger pump (110) and an oil leakage port of the plunger pump (110) are respectively connected with the hydraulic oil tank (100);

an oil inlet of the switching valve bank (120) is connected with an oil outlet of the plunger pump (110), a first load sensitive port of the switching valve bank (120) is connected with a load sensitive control oil port of the plunger pump (110), and an oil return port of the switching valve bank (120) is connected with the hydraulic oil tank (100);

an oil inlet of the lifting valve group (130) is connected with a first oil outlet of the switching valve group (120), and an oil return port of the lifting valve group (130) is connected with the hydraulic oil tank (100);

an oil inlet of the steering valve group (140) is connected with a second oil outlet of the switching valve group (120), a load sensitive feedback port of the steering valve group (140) is connected with a second load sensitive port of the switching valve group (120), and an oil return port of the steering valve group (140) is connected with the hydraulic oil tank (100);

a load-sensitive overflow valve group (150) arranged between a load-sensitive feedback port of the steering valve group (140) and a second load-sensitive port of the switching valve group (120);

the oil inlet of the switching valve group (120) is selectively communicated or disconnected with the first oil outlet of the switching valve group (120), and the first load sensitive port of the switching valve group (120) is selectively communicated or disconnected with the second load sensitive port of the switching valve group (120).

2. The hydraulic steering and lifting system of claim 1, further comprising:

a first lift cylinder (160) and a second lift cylinder (170);

an oil inlet of the first floating valve group (180) is connected with a first working oil port of the lifting valve group (130), and an oil outlet of the first floating valve group (180) is respectively connected with rod cavities of the first lifting oil cylinder (160) and the second lifting oil cylinder (170);

an oil inlet of the second floating valve group (190) is connected with a second working oil port of the lifting valve group (130), and an oil outlet of the second floating valve group (190) is connected with rodless cavities of the first lifting oil cylinder (160) and the second lifting oil cylinder (170) respectively.

3. The hydraulic steering and lifting system of claim 2, further comprising:

the steering system comprises a first steering oil cylinder (200) and a second steering oil cylinder (210), wherein a first working oil port of a steering valve group (140) is respectively connected with a rod cavity of the first steering oil cylinder (200) and a rodless cavity of the second steering oil cylinder (210), and a second working oil port of the steering valve group (140) is respectively connected with the rodless cavity of the first steering oil cylinder (200) and the rod cavity of the second steering oil cylinder (210);

an oil inlet of the steering valve group (140) is selectively communicated or disconnected with a first working oil port of the steering valve group (140) and a second working oil port of the steering valve group (140).

4. The hydraulic steering and lifting system of claim 3,

the switching valve group (120) comprises a first check valve (122), a second check valve (124), a third check valve (126), a constant flow valve (128), a first throttling plug (220), a second throttling plug (222), a first electromagnetic directional valve (224), a logic valve (226) and a first overflow valve (228);

the first check valve (122) is located between an oil inlet of the switching valve group (120) and a second oil outlet of the switching valve group (120), and the second check valve (124) is located between a second oil outlet of the switching valve group (120) and an emergency steering oil inlet of the switching valve group (120);

an oil inlet of the first electromagnetic directional valve (224) is connected with an oil inlet of the switching valve group (120), the constant flow valve (128) and the first throttling plug (220) are arranged between the oil inlet of the switching valve group (120) and the oil inlet of the first electromagnetic directional valve (224), an oil outlet of the first electromagnetic directional valve (224) is connected with a second load sensitive port of the switching valve group (120), the second throttling plug (222) is arranged between the oil outlet of the first electromagnetic directional valve (224) and the second load sensitive port of the switching valve group (120), the third check valve (126) is arranged between a first working oil port of the first electromagnetic directional valve (224) and a second working oil port of the first electromagnetic directional valve (224), a first working oil port of the first electromagnetic directional valve (224), an oil inlet of the switching valve group (120) and the constant flow valve (128) are all connected with the oil inlet of the logic valve (226), an oil outlet of the logic valve (226) is connected with the first working oil port of the switching valve group (120), and the second working oil port of the switching valve group (224) is connected with the second load sensitive port of the switching valve group (224).

5. The hydraulic steering and lifting system of claim 4, further comprising:

the hydraulic control system comprises a pilot oil source valve group (230), wherein the pilot oil source valve group (230) is respectively connected with a first control port of the lifting valve group (130) and a second control port of the lifting valve group (130), and an oil return port of the pilot oil source valve group is connected with a hydraulic oil tank (100).

6. The hydraulic steering and lifting system of claim 5,

the pilot oil unit valve group (230) comprises a pressure reducing valve (232), a second overflow valve (234), an accumulator (236), a third throttling plug (238) and a second electromagnetic reversing valve (240);

an oil inlet of the pilot oil element valve group (230) is sequentially connected with the pressure reducing valve (232), the third throttling plug (238) and an oil inlet of the second electromagnetic directional valve (240), a first working oil port of the second electromagnetic directional valve (240) is connected with a first control port of the lifting valve group (130), and a second working oil port of the pilot oil element valve group (230) is connected with a second control port of the lifting valve group (130).

7. The hydraulic steering and lifting system of any one of claims 1-6, further comprising:

an oil inlet of the emergency pump (250) is connected with the hydraulic oil tank (100);

an emergency steering valve group (260), an emergency steering oil inlet of the switching valve group (120) is connected with an oil outlet of the emergency steering valve group (260), and an oil outlet of the emergency steering valve group (260) is selectively communicated with the hydraulic oil tank (100) and the emergency pump (250).

8. The hydraulic steering and lifting system of claim 7,

the emergency steering valve group (260) comprises a first safety valve (262), a hydraulic control reversing valve (264) and a fourth one-way valve (266);

a first oil outlet of the hydraulic control reversing valve (264) is connected with an oil outlet of the emergency steering valve group (260), the fourth one-way valve (266) is arranged between the first oil outlet of the hydraulic control reversing valve (264) and the oil outlet of the emergency steering valve group (260), a second oil outlet of the hydraulic control reversing valve (264) is connected with the hydraulic oil tank (100), and an oil inlet of the hydraulic control reversing valve (264) is connected with an oil outlet of the emergency pump (250);

the emergency pump (250) comprises a bridge circuit.

9. Hydraulic steering and lifting system according to any of claims 2-6,

the lift valve block (130) includes a fifth check valve (132), a second relief valve (134), and a main spool (136);

the oil inlet of the main valve core (136) is connected with the oil inlet of the lifting valve group (130), the fifth check valve (132) is located between the oil inlet of the main valve core (136) and the oil inlet of the lifting valve group (130), and the oil inlet of the main valve core (136) is selectively communicated or disconnected with the oil inlet of the first floating valve group (180) and the oil inlet of the second floating valve group (190).

10. A dump truck, comprising:

a hydraulic steering and lifting system according to any one of claims 1-9.

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